#!/usr/bin/env python

# python-gphoto2 - Python interface to libgphoto2
# http://github.com/jim-easterbrook/python-gphoto2
# Copyright (C) 2015  Jim Easterbrook  jim@jim-easterbrook.me.uk
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from __future__ import print_function

import io
import logging
import os
import subprocess
import sys

from PIL import Image

import gphoto2 as gp

def main():
    logging.basicConfig(
        format='%(levelname)s: %(name)s: %(message)s', level=logging.WARNING)
    gp.check_result(gp.use_python_logging())
    context = gp.gp_context_new()
    camera = gp.check_result(gp.gp_camera_new())
    gp.check_result(gp.gp_camera_init(camera, context))
    # required configuration will depend on camera type!
    print('Checking camera config')
    # get configuration tree
    config = gp.check_result(gp.gp_camera_get_config(camera, context))
    # find the image format config item
    OK, image_format = gp.gp_widget_get_child_by_name(config, 'imageformat')
    if OK >= gp.GP_OK:
        # get current setting
        value = gp.check_result(gp.gp_widget_get_value(image_format))
        # make sure it's not raw
        if 'raw' in value.lower():
            print('Cannot preview raw images')
            return 1
    # find the capture size class config item
    # need to set this on my Canon 350d to get preview to work at all
    OK, capture_size_class = gp.gp_widget_get_child_by_name(
        config, 'capturesizeclass')
    if OK >= gp.GP_OK:
        # set value
        value = gp.check_result(gp.gp_widget_get_choice(capture_size_class, 2))
        gp.check_result(gp.gp_widget_set_value(capture_size_class, value))
        # set config
        gp.check_result(gp.gp_camera_set_config(camera, config, context))
    # capture preview image (not saved to camera memory card)
    print('Capturing preview image')
    camera_file = gp.check_result(gp.gp_camera_capture_preview(camera, context))
    file_data = gp.check_result(gp.gp_file_get_data_and_size(camera_file))
    # display image
    data = memoryview(file_data)
    print(type(data), len(data))
    print(data[:10].tolist())
    image = Image.open(io.BytesIO(file_data))
    image.show()
    gp.check_result(gp.gp_camera_exit(camera, context))
    return 0

if __name__ == "__main__":
    sys.exit(main())
